Add support for nuget package generation

Fixes labstreaminglayer#2

examples/Directory.Build.props

@@ -1,6 +1,9 @@
 <Project>
-<Import Project="$([MSBuild]::GetPathOfFileAbove('Directory.Build.props', '$(MSBuildThisFileDirectory)../'))" />
   <PropertyGroup>
+    <Authors>Christian Kothe</Authors>
+    <TargetFramework>netstandard2.0</TargetFramework>
+    <Version>1.12.2</Version>
     <LangVersion>8.0</LangVersion>
   </PropertyGroup>
-</Project>
+</Project>
+

liblsl.csproj

@@ -7,6 +7,15 @@
     <Version>2.0</Version>
     <DefaultItemExcludes>$(DefaultItemExcludes);examples/**</DefaultItemExcludes>
     <AssemblyName>lsl_csharp</AssemblyName>
+    <Copyright>Copyright © Christian Kothe 2021</Copyright>
+    <ProjectUrl>https://github.com/labstreaminglayer/liblsl-Csharp</ProjectUrl>
+    <PackageLicenseExpression>MIT</PackageLicenseExpression>
+    <PackageTags>LSL Lab Streaming Layer</PackageTags>
+    <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
+    <RuntimeIdentifiers>win-x86;win-x64;osx-x64;linux-x64</RuntimeIdentifiers>
   </PropertyGroup>
-</Project>
 
+  <ItemGroup>
+    <Content Include="runtimes\**" Exclude="runtimes\README.md" PackagePath="runtimes" />
+  </ItemGroup>
+</Project>

runtimes/README.md

@@ -0,0 +1,3 @@
+# Runtime Identifier Dependencies
+
+The NuGet package for the C# bindings includes binary distributions for major platform runtimes targeted by [liblsl](https://github.com/sccn/liblsl). To successfully build the package, these binaries need to be downloaded from [liblsl releases](https://github.com/sccn/liblsl/releases) and included in this folder following the RID naming conventions outlined in the [RID Catalog](https://docs.microsoft.com/en-us/dotnet/core/rid-catalog).